This study examines the prevalence and correlates of psychiatric disorders and substance use among pregnant and postpartum women in the United States. Using data from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), the researchers found no significant differences in the 12-month prevalence of psychiatric disorders between past-year pregnant, postpartum, and non-pregnant women of childbearing age, except for a higher prevalence of major depressive disorder in postpartum women. Past-year pregnant and postpartum women had lower rates of alcohol use disorders and any substance use, except illicit drug use, compared to non-pregnant women. Factors such as age, marital status, health status, stressful life events, and history of trauma were associated with higher risk of psychopathology in these groups. Most women with psychiatric disorders did not receive mental health care, highlighting the need for improved recognition and treatment for mental disorders during pregnancy and the postpartum period. The study underscores the importance of targeted prevention and early intervention efforts for vulnerable groups identified in the analysis.This study examines the prevalence and correlates of psychiatric disorders and substance use among pregnant and postpartum women in the United States. Using data from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), the researchers found no significant differences in the 12-month prevalence of psychiatric disorders between past-year pregnant, postpartum, and non-pregnant women of childbearing age, except for a higher prevalence of major depressive disorder in postpartum women. Past-year pregnant and postpartum women had lower rates of alcohol use disorders and any substance use, except illicit drug use, compared to non-pregnant women. Factors such as age, marital status, health status, stressful life events, and history of trauma were associated with higher risk of psychopathology in these groups. Most women with psychiatric disorders did not receive mental health care, highlighting the need for improved recognition and treatment for mental disorders during pregnancy and the postpartum period. The study underscores the importance of targeted prevention and early intervention efforts for vulnerable groups identified in the analysis.